A pivotal sash window adapted for installation in a master frame of a sash window assembly is well-known. The sash window assembly typically has opposed, vertically extending guide rails to enable vertical reciprocal sliding movement of the sash window in the master frame while cooperatively engaged with the guide rails. The sash window has a top sash rail, a base and a pair of stiles cooperatively connected together at adjacent extremities thereof to form a sash frame, usually a rectangular frame. Typically, a pair of spaced tilt-latches are installed on, or in, opposite ends of the top sash rail.
Each tilt-latch is generally comprised of a housing having an outward end opening and a latch bolt disposed within the housing. A spring disposed within the housing generally biases the latch bolt through the outward end opening to engage the guide rails of the master frame. The latch bolt has a control button to allow for actuation of the latch bolt. An operator can use his finger to engage the button and actuation of the latch bolt. An operator can use his finger to engage the button and actuate the latch bolt wherein the latch bolt is retracted into the housing. This releases the latch bolt from the guide rail. When the latch bolts of the opposed tilt-latches are actuated simultaneously, the sash window can then be pivoted from the master frame.
A tilt-latch mounted in a top sash rail is typically called a flush-mount tilt-latch. An example of this type of tilt-latch is shown in U.S. Pat. No. 5,139,291, assigned to Ashland Products, Inc., the assignee of the present invention. To accommodate the flush-mount tilt-latch in the top rail, a slot is punched or routed in the top rail. Because material is removed from the top rail, the structural integrity of the top rail is decreased. The greater the length of the tilt-latch, the greater the amount of material that is required to be removed from the top rail, and thus, the greater effect on the structural integrity of the top rail.
As discussed, the window sash is fixed to the master frame by the nose of the latch bolt that engages the guide rail of the master frame. When wind forces act upon the window sash, a moment can be created about the point where the nose engages the guide rail. A moment arm associated with this moment corresponds to the length of the tilt-latch. The greater the length of the tilt-latch, the greater the moment that can be generated. This can possibly result in the latch bolt nose disengaging from the guide rail allowing the sash window to pivot uncontrollably from the master frame. Also, because holes have been punched into the top rail to accommodate the tilt-latches, a bowing of the top rail could occur under sufficient wind conditions. The wind forces may apply a twisting force on the tilt-latch in the top rail. Wind forces acting on the sash window may also apply torsional forces between the latch bolt and the housing.
There are a large number of different sash window assemblies commercially available. It is not uncommon for the dimensions of the assembly components, including the guide rails, to vary. Variances in the size of the guide rails can affect the operation of the tilt-latch and, in particular, the latch bolt. For example, in some situations, the guide rails can be manufactured having a smaller depth. A guide rail having a smaller depth affects the space that accommodates the nose of the latch bolt that extends from the tilt-latch housing. A latch bolt nose could “bottom-out” against a rear wall of the guide rail having a smaller depth. Guide rails often include a sash balance cover to cover balance springs normally included in sash window assemblies. The sash balance cover may be hot-stamped for cosmetic appearances. The latch bolt nose that extends too far out of the housing can bottom-out and rub against the sash balance cover. This can leave marks thereby undesirably changing the cosmetic appearance of the cover. In these situations, it is desirable to having the ability to adjust the distance that the latch bolt nose extends out of the housing to thereby control the depth of penetration of the latch bolt nose into the guide rail.
The present invention is provided to solve these and other problems.